Silicone Coating Your Metal Roof: The Ultimate Guide [2022]

Most warehouse roofs are metal. But metal roofing can be found on all types of buildings including industrial or commercial buildings.

Metal roofs offer plenty of advantages with one being longevity. It’s true that metal roofs could last 70 years!

However, they do not last forever, and like with anything they do at some point need to be replaced or restored.

One popular method of metal roof restoration is an acrylic or silicone cool roof coating. Both acrylic and silicone coatings work well with all types of roofing substrates but there are mixed reviews on whether or not silicone coatings are actually effective on a metal roof.

With the mixed reviews, some people may be hesitant to coat their metal roof, but are the doubts legitimate? Join me and let’s dive right in.

Who is Central Roofing Company? 

But first I should state who is Central Roofing before I go on and why you should listen to our advice.  Central Roofing is a commercial roofing company based out of Los Angeles, with over 30 years of experience. Some of our clients include See’s Candies, 20th Century Fox, and Cushman & Wakefield to name a few.

We have provided over 30 million Cool Roof Coatings in 30 years of servicing commercial roofs in Southern California. 

Types Of Metal Roofs:

Metal roofing is the most expensive option for commercial buildings and some kind of slope is a must to get the most out of the possible lifespan of metal.

But the upside is that the metal roof will outlive almost everything else in the building.

It’s not an exaggeration that some metal roofs will last 70 years or more.

It comes in three basic forms: sheets, tiles, and look-alikes. The look-a-like option just means the metal is designed to look like something else such as a cedar shake.

Steel roofing materials are the most common and most mid-grade price option. It is often coated or mixed with another material to increase some kind of resistance factor for specific uses. Galvanized steel has a zinc coating to increase corrosion resistance; galvalume steel is coated with aluminum to increase reflectivity and corrosion resistance, for example.

Aluminum roofing is a pricier option but more durable. Its price often restricts its use to smaller buildings or sections of commercial buildings. It is a lighter metal for lower-durability roofs or easier installation. It is also easier to work with and is more easily fitted to roof interruptions.

Zinc roofing is a must for high-stress environments, especially those with high chemical or saline water exposure such as cities, industrial areas or coastal areas. Zinc is also easy to fit roofing specifics. But it is also pricey. That’s why it is often used with other metals.

Benefits of Metal Roofs:

Along with metal roofs having great longevity, they’re also aesthetically pleasing. The membranes of metal roofs can come in various colors and as mentioned earlier can look-a-like different materials. This gives building owners the flexibility to choose however they want their metal roof to look.

Also. metal roofs in general are more cost-effective in the long run compared to traditional roofing materials. The minimal maintenance, long lifespan, and energy efficiency offered by metal roofs reduce your upkeep and operating costs.

You free up some funds, which you can allocate for other business-critical causes.

Finally, they also lower your carbon footprint because metal roofs are 100% recyclable so they won’t clog up landfills. And of course, can be cool roof coated which we will discuss further below.

What is a Silicone Coating?

A silicone roof coating is a type of liquid-applied Roofing. These types of systems are de facto custom-fitted roofing solutions because they can be painted on or around nearly any existing roofing structure or fixture.

The liquid materials are also seamless and monolithic. In other words, it’s just one big layer and they need to be applied to an existing roof structure. Silicone Roof Coatings are the most prominent cool roof coating in the market today and are a great way to improve the look and performance of your roof.

What Are The Negative Reviews On Silicone Coating a Metal Roof?

There are plenty of commercial roofing contractors that state that a roof coating most notably a silicone roof coating, after year 5, starts to hold the water due to small holes that start to appear on the silicone coating.

The water is holding underneath the coating with the bits of water penetrating the silicone. Although appearing nice on the outside if you peel the coating off, you’ll see the rust underneath as well as moisture trapped underneath. To make matters worse with the sun beating down on the metal roof this combination is causing the roof to deteriorate faster, which of course, is not good.

Metal Roof Peel

Also, at the joints, doubters say that coatings cannot sit properly leaving gaps in the silicone which again causes moisture to get trapped and deteriorate the roof faster.

Are These Legitimate Concerns?

Absolutely! All of the concerns are legitimate. It’s true and valid and In fact, with all those issues it’s better to have not coated the metal roof at all.

But there is an important BUT.

With Silicone Coatings and Acrylic coatings, the key to them being effective is preparation. Silicone coatings and acrylic can be very effective at protecting your metal roof and also reflecting the sun’s harmful U.V rays which in turn causes the indoor temperature to be more comfortable without turning on an a/c.

Silicone coatings were designed specifically to endure ponding water by not absorbing water after curing.

So the issue with a metal roof silicone coating isn’t so much with the silicone coating material itself but rather the preparation.

Metal Roof Preparation Is The Key.

With any type of commercial flat roof, in order for a coating to be effective the preparation before the application is key. With metal roofs, this entails pressure washing the metal roof.

Additionally, the seams of the roof must be taped with the fasteners completely coated before coating the rest of the roof. After the initial coating, the seams should get an additional coating for added protection. This is to prevent any gaps so that there isn’t any water that could be trapped and cause the metal roof to deteriorate faster.

Once the seams have been cured, commercial roofers should then apply two coats of coating in short smooth overlapping passes. Once the first coat is cured the second is applied in the manner. The result is a silicone-coated commercial metal roof that should give you at least another 20 years of life.

Successful Cool Roof Coating Case Studies

The urban heat island (UHI) is the phenomenon in which there is a high concentration of dark surfaces, such as roofs and roads combined with a lack of trees and shade. Heat islands can become dangerous when they cause heat-related illnesses or death. Additionally, they strain the energy grid because they require a/cs to run nonstop and to work harder.

Cool Roof Mitigate Urban Heat Island'sTo combat this scientists created cool roofs to mitigate Urban Heat Islands.

In late 2014 Barcelona City Council in Spain, teamed with Dow Chemical Company where they applied a cool roof coating on a flat commercial building, the result was the temperature of the roof went from 78 degrees Fahrenheit (25.8 Celsius) to 57 degrees Fahrenheit (13.8 Celsius). That is an over 20 degrees Fahrenheit drop!

Cool Roof Commercial CoatingAdditionally, science direct conducted a study in Jamaica where they applied a cool roof coating on a single-story semi-detached flat roof house. Afterward, they monitored the temperature inside the house for a year. In just one month the room air temperature inside was significantly cooler. Not only that but it continued throughout the year.

Cool Roof Coating Benefit

Looking at the red line curves which is measuring the hot air indoors, you can clearly see on the chart to the right, that after a cool roof was installed the indoor temperature drastically dropped.

Even though both studies we’re not on metal roofs specifically, they do show the significant impact cool roof coatings have on slowing the deterioration of the roof as well as potential energy savings.

Maintenance is Imperative.

In that same science direct study in Jamaica, they also found that there is very little solar reflectivity loss due to aging but rather loss due to the accumulation of dirt. Unfortunately, one of the biggest cons of silicone roof coatings is the accumulation of dirt that occurs on this type of coating. This makes maintenance imperative to your metal roof coating.

Maintenance will have to include cleaning and re-applying cool roof coatings. At Central Roofing we recommend our clients an inspection at least twice a year.
If you have a warehouse metal roof don’t let it stop you from getting a cool roof coating but do your due diligence

Not All Commercial Roofers Are Equal

It’s imperative that no matter what type of commercial roofing system you have or thinking about installing that you do your due diligence. Make sure they’re licensed roofers. It’s one thing to have a business license and it’s another thing to actually hold a roofing license. Why? Because a business license is just for tax purposes, a roofer’s license backs up that they can actually perform roofing services.

As we mentioned for metal roofs, preparation is key, we meant that quite literally in roofing prepping the metal roof for a silicone coating but also preparing to hire the right roofer to do the job correctly.

This has to include checking out the potential commercial roof contractor’s customer reviews and their roof warranties.

Commercial Roofing Warranties 

A roofer’s warranty shows you the confidence they have behind their work. In roofing, there are two types of warranties; workmanship and manufacture warranties.

Manufacturer No Dollar Limit (NDL) Warranty

The NDL in the manufacturer’s NDL warranty stands for “no dollar limit.” This means the manufacturer must fully cover all defective products. Thus, if fixing the roof costs more than the initial cost of roof installation, the manufacturer will pay for the repairs.

Manufacturer’s Materials Warranty

The materials warranty is a time-sensitive warranty, guaranteeing the roofing materials will not fail within a given time period. Typically the time period stretches between 10 and 30 years.

The materials warranty will not cover materials your roofing contractor uses if the manufacturer did not produce those materials.

Manufacturer’s Labor and Material Warranty

The labor and material warranty is typically a limited type of warranty. This means it will only cover a given dollar amount of damage.

Thus, the size of your roof matters in regards to the labor and material warranty since the bigger your roof is, the more fixing it will cost.

Often manufacturers will prorate this type of warranty. Thus the coverage amount goes down as time passes.

Manufacturer’s Roof System Warranty

The roof system warranty applies specifically to the roofing system’s membrane. Thus often manufacturers will refer to this warranty as the “membrane only” warranty.

The roof system warranty will not cover the decking or insulation. It can come with a no-limit or no-dollar-limit coverage.

Roofing Contractor Warranties

The roofing contractor warranty refers to the work the contractor performs to install the roof. It also covers the products the contractor uses to install your roofing.

Often labor warranties last only five years, and some will last as short as just one year. Regardless, you can often negotiate a time frame with your contractor.

Ways to Void Your Warranty

When you have a new commercial roof installed, plan on regular commercial roof maintenance with a professional, insured roofing contractor. This will help maintain the health of your roof and will protect your warranty.

Just a few missteps will void your warranty. Avoid the following scenarios.

Unauthorized Roofing Changes

Sometimes you want to change or improve your roof. But when you do this, you need to make sure you have authorized roofing contractors complete the roof.

For example, a new air conditioning unit or extra ventilation can compromise your new roof. Improperly installed, this type of modification will cause hidden leaks. When you attempt to repair your roof on your own or save a few bucks by calling in an inexperienced repairman, you may end up paying far more than you anticipated.

You will void your warranty when you authorize certain changes to your roof. Look at the warranty agreement and read the fine print to make sure your warranty covers the changes you want,

Damage Left Too Long

Inspect your roof regularly, especially after a major storm. Make sure your document and report all damage to your insurance company and the roofing contractor that installed your roof.

Letting damage go too long will void your warranty, and sometimes your insurance as well. Keep photos on hand of your roof in good shape as well as its damaged shape so you have before and after documentation.

Roofs are not cheap, and if the roofing contractor you hire doesn’t know what they’re doing it could cost you even more.

Find An Experienced Commercial Roofer

Experience is a critical component for metal roof buyers when selecting a contractor. A contractor with years of experience offers obvious benefits over those new to installing residential metal roofing.  

More experienced roofing contractors are also familiar with a broader range of roofing situations and are presumably better equipped to deal with them.

Lastly, remember that price is important, but it is not the only consideration. Most people are willing to pay a few dollars more for a responsive, available, and courteous contractor who has the right level of experience installing metal roofing.

How To Find Grants & Rebates for Commercial Cool Roofs?

To help commercial building owners and property managers find incentives to install a cool roof, developed a Funding Wizard tool to help individuals and businesses fund their cool roofing projects.

The Cool Roof Cost Calculator Tool

If you’re not quite ready to have a commercial roofing contractor come out to your building no problem. Our  Cool Roof Calculator can give you a cool roof estimate within minutes and guess what? it’s completely free.

Though the calculator does its best job to provide an accurate estimate of the cost of a cool roof. It still cannot be as accurate as a physical inspection.

But the calculator is completely free to use, and users are able to receive a rough estimate of just how much acrylic roofing coatings or silicone roof coatings would cost them.

Also, you don’t have to deal with the hassle of calling roofing company after roofing company to get someone out to your property, and then have to deal with the annoying and pushy sales calls afterward. This tool doesn’t require any contact information from you, no solicitation whatsoever, it is truly free. 


Cool Roof coatings have plenty of benefits for all types of roofs, TPO, PVC, Modified-Bitumen, Built-Up-Roofing, and metal roofs included. But with a metal roof it’s imperative you do your research.

And afterward, if you do find that fluid applied cool roof coating is the right solution for your metal roof if the preparation and application are done correctly and you maintain your roof in the years afterward there is no doubt that a cool roof can absolutely work on your warehouse or commercial metal roof.


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